const {Writable} = require('stream')

class MyWriteable extends Writable{
  constructor(){
    super()
  }
  _write(chunk,en,done){
    process.stdout.write(chunk.toString()+'<---')
    process.nextTick(done)
  }
}

const myWriteable = new MyWriteable()

myWriteable.write('拉钩教育','utf-8',()=>{
  console.log('end');
})
